Silencing of stemness genes increases the sensitivity of hepatocellular carcinoma cells to gamma radiation.

<p><b>A and B</b> HepG2 cells (a) and Huh7 cells (b), were transfected with 100 nM of aiRNA targeting GFP, Sox2 or Oct4, and knockdown efficiency was evaluated by Western blot after 48 hours. Sox2 and Oct4 belong to the same regulatory circuit; therefore, single gene knockdown leads to reduced expression levels of both proteins. <b>C and D</b> HepG2 and Huh7 cells transfected with aiRNA targeting GFP, Sox2 or Oct4 were irradiated with 0, 2, 4, 6, 8 or 10 Gy of gamma radiation and equal numbers of cells were plated onto 6-well plates for colony formation assay. On day 7, colonies were counted and the fraction of surviving clonogenic cells expressed as a natural log was plotted. Lines are fitted using a first-order polynomial regression and represent the mean of four independent experiments. *p<0.05, **p<0.01, ***p<0.001 versus GFP-transfected cells.